Crown height is the height of the crown, from the girdle to the table. It is a percentage of the average diameter.
In more detail
It follows from the table and the crown angle: half of (100% − table) × the tangent of the crown angle. For the T73's 53% table and 34.5° crown, that is about 16%. GIA's Excellent limit for crown height alone is 12.5% to 17.0%.
On a grading report
On the proportion diagram as a percentage. IGI's Ideal band is 13 to 16.5%.
Related terms
- Crown angle: The crown angle is the slope of the bezel facets, measured against the plane of the girdle.
- Table size: Table size is the width of the table as a percentage of the average diameter.
- Total depth: Total depth is the height of a stone from table to culet as a percentage of its average diameter. It equals crown height + girdle thickness + pavilion depth.
- Crown: The crown is the part of a cut stone above the girdle. On a standard round brilliant it has 33 facets: the table, 8 stars, 8 bezels and 16 upper halves.